RT Journal Article
T1 Modeling the Temperature-Dependent Material Dispersion of Imidazolium-Based Ionic Liquids in the VIS-NIR
A1 Arosa Lobato, Yago
A1 Algnamat, Bilal Saleh Mohammad
A1 Rodríguez-Fernández, Carlos Damián
A1 López Lago, María Elena
A1 Varela Cabo, Luis Miguel
A1 Fuente Carballo, Raúl de la
K1 Alkyls
K1 Anions
K1 Colloids
K1 Optical properties
K1 Quantum mechanics
AB A thorough analysis of the refractive index of 11 1-alkyl-3-methylimidazolium-based ionic liquids with three different anions, tetrafluoroborate (BF4), bis(trifluoromethylsulfonyl)imide (NTf2), and trifluoromethanesulfonate (OTf), is reported. Refractive indices were estimated, in the temperature interval from 298.15 to 323.15 K, using an Abbe refractometer to determine the value at the sodium D line and white light spectral interferometry to obtain dispersion in the range of wavelengths from 400 to 1000 nm. The first part of the manuscript is focused on the dependence of refractive index with wavelength, temperature, cation alkyl chain length, and anion nature. Once the main features are detailed, and in order to explain the experimental trends, a model for the refractive index is considered where its square is expressed by a single resonance Sellmeier dispersion formula. This formula has two coefficients: the first one identifies the position of the resonance in the spectral axis, and the second one specifies its strength. It was found that, for a given compound, the resonance’s position is independent of temperature, while the strength varies linearly with it. This model reproduces successfully the experimental data within the refractive index uncertainty. Furthermore, the model allows calculating the thermo-optic coefficient and its wavelength dependence.
PB American Chemical Society Publications
SN 1932-7447
YR 2018
FD 2018-11-27
LK http://hdl.handle.net/10347/32128
UL http://hdl.handle.net/10347/32128
LA eng
NO Ministerio de Economı́a y Competitividad (MINECO)(MAT2014-57943-C3-1-P,  MAT2014-57943-C3-2-P,MAT2017-89239-C2-1-P), Xunta de Galicia, and FEDER(AGRUP2015/11, GRC ED431C 2016/001, ED431D 2017/06, ED431E 2018/08) are acknowledged. C.D.R.F. thanks thesupport of Xunta de Galicia through the grant ED481A-2018/032.
DS Minerva
RD 23 abr 2026